This is a 59 year-old man with a 4 year history of worsening short-term memory and difficulty expressing himself. On initial exam, he misspoke frequently and made a number of spelling errors when asked to write a sentence. He could not draw a clock. He was unable to recall 3 words after a short delay. He scored an 18/30 on the Mini-mental exam. An MRI of the brain was normal.

This PET CT scan shows diminished blood flow in the parietal and temporal lobes bilaterally along with decreased flow to the posterior cingulate gyrus. This is typical for Alzheimer’s disease.